Vane construction



1954 J. GASSMANN ETAL 97 VANE CONSTRUCTION Filed Jan. 8, 1959 INVENTORSJOHANNES GASSMANN EUGEN S. NEHER BY ATTORNEYS United States Patent3,1635% FAME CfiNSTRUtITlQN Johannes Gassrnann, Aitbach, near Essiingen(Neckar), and Eugen S. Neher, dtuttgart-Qherturlrheim, Germany,assignors to Daimler-Benz Airtiengesellschaft, Stuttgart- Unterturkheim,Germany 7 Filed Jan. 8, 1959, Ser. No. 785,600

fliaims priority, appiication Germany Jan. 14, N53

4- Claims. (Cl. 253-77) The present invention relates to vanes or bladesfor use in flow devices such as turbines which are exposed to arelatively high temperature.

The present invention is particularly concerned with the problem ofproducing a guide vane construction for gas turbines which is capable ofeffectively resisting the relatively high temperatures prevailingtherein without burning up or melting. Additionally, the guide vaneconstruction in accordance with the present invention is to exhibit acorrosion-resistant characteristic, i.e., is to be as corrosion-free aspossible, and is adapted to be manufactured relatively inexpensively.

Furthermore, the present invention is also concerned with the problem ofrendering especially the guide vanes in gas turbines relativelyinsensitive against sudden temperature changes, i.e., against so-calledheat shocks.

It is known in the prior art to manufacture the vanes for gas turbinesfrom ceramic materials.

It is further knownin the prior art to utilize for the manufacture ofvanes for use in gas turbines special alloy steels which possesssuificient rigidity even with the relatively high temperatures and arealso corrosion-resistant or non-corrosive, such as, for example,stainless or rust-free steel alloys.

However, the ceramic vanes used in the prior art have the disadvantagethat they are not sufficiently safe or resistant to breakage.

Turbine vanes made of a highly alloyed heat-resistant steel have arelatively much larger weight than the ceramic vanes and areadditionally very expensive.

The present invention aims at a vane construction obviating theaforementioned disadvantages of the prior art.

The present invention consists in providing a vane made in part ofceramic material and in part of metallic material, and in which the vanebody, properly speaking made of ceramic material, is provided with oneor several recesses, bores, apertures, hollow or cut-out portions intowhich one or several metallic supporting inserts are placed. Therecesses or cut-out portions are preferably arranged within the interiorof the ceramic vane body so that the support member placed into acorresponding recess is surrounded like a core by the ceramicvane bodyportion.

According to a further feature in accordance with the present invention,the ceramic-body vane portion may be constructed either as a one-pieceintegral element or of It is thereby particularly advantageous severalparts. if the ceramic-body portion is subdivided transversely andconsists of individual vanes which are stacked or placed upon themetallic core member. This metallic core member is thereby preferablymade of a high-heat-resistant steel. With such a construction, theceramic vane is far-reachingly safeguarded by the interior supportthereof in the form of the metallic core against breakage. The supportinsert is appropriately matched or adapted in its configuration to thegeneral shape of the vane constituted by transversely subdivided vanebody portions and is constructed approximately in the form of a circularsegment.

The multi-partite construction of the ceramic vanebody portion offers inparticular the advantage that such vanes are relatively insensitiveagainst sudden temperature changes, particularly against the so-calledheat shocks,

Accordingly, it is an object of the present invention to provide a vaneconstruction for use in flow devices,

particularly for use in gas turbines, which obviates the provision of aguidevane construction, particularly for use in gas turbines, which isrelatively insensitive to,

changes in temperatures and particularly to the so-called heat shockswhich occur in gas turbines.

These and other objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIGURE 1 is a cross-sectional view through a guide vane construction ofa gas turbine in present invention, H

FIGURE '2 is a top plan view of the guide vane construction shown inFIGURE 1, and

FIGURE 3 represents a structural modification of the guide vaneconstruction illustrated in FIGURE 1.

Referring now to the drawing wherein like reference numerals are usedthroughout the two views FIGURES 1 and 2 to designate correspondingparts, reference numeral 1 generally designates therein the guide vaneconstruction in accordance with the present invention which is providedin the center part thereof with a reinforcing supporting insert 2 madeof a high-heat-resistant alloy steel. The center part 2 represents thecore member of the guide vane. The corevmember 2 thereby has the shapeof a part of a circle and' is surrounded by the ceramic vane-bodyportion 3.

accordance with the FIGURE 2 shows that the surrounding body portion 3consists of a plurality of individual elements such as lamina members 4which are placed or stacked one above the other and are retainedtogether by the metallic supporting insert 2. ,The individual elements 4abut against one another along the separating joints or edge portions 5extending in a direction transversely to the longitudinal direction ofthe guide vane as may be readily recognized in FIGURE 2.

In contrast to the subdivided construction of the ceramic body portion 3made of a plurality of individual elements 4, the central supportinginsert 2 of the guide vane il lustrated in the drawing consists of anintegral or'interconnected metallic body. v I

While we have shown one'ernbodiment in accordance with the presentinvention, it is understood that the same is not. limited thereto but issusceptible of many changes and modifications within the spirit andscope of the present invention. For example, instead of a singlereinforcing insert 2, the ceramic body portion 3 of the guide vane maybe provided with two or more hollow or cut-out portions or recesses forthe accommodation therein of two or more reinforcing supporting insertsas shown in FIG- URE 3 each made of an integral high-heat-resistantsteel alloy. In this figure the inserts are designated by referencenumeral 2', the guide vane construction by reference numeral 1 and theceramic body portion by 3. Furthermore, the ceramic body portions 3 or 4may be secured Patented Dec. 29, 1964 t to the core memberZ in anysuitable conventic nalimanner known in the prior art. 1

Thus, the present invention is not limited to the specific embodimentillustrated herein but is susceptible of many changes and modificationsWithout departing from the spirit and scope of the. present invention,and we, there-.

fore, do not wishto be limitedto the specific embodiment illustratedherein but. intendv to cover all such changes and modifications as areencompassed by the scope of the appended claims.

We claim:

1; A vane construction for flow devices. exposed to a relatively hightemperature, especially for use as guide vanes in gas turbines,comprising an outer body portion made of ceramic material and formingthe vane body,

said ceramic body portion being provided with recessv means, andmetallic reinforcing insert means in said recess means for supportingthereon said ceramic body portion, said'ceramicouter body portion havinga structure adapting said body portion to withstand heat shocks, "saidstructure comprising a plurality of lamina members having abutmentsurfaces abutting each other, said surfaces extending essentiallytransversely with respect to the longitudinal direction of said bodyportion said lamina members being emplaced over said metallicreinforcing insert means.

2. A vane construction according to claim 1, wherein said reinforcinginsert means is in the form of an approximately circular segment forminga supporting core, and wherein said plurality of lamina members areessentially identical and surround said supporting core.

3. A vane construction according to claim 2, wherein said supportingcore is made of steel alloy retainingits yield strength at hightemperatures.

4. A vane construction for flow devices exposed to a relatively hightemperature, especially for use as a guide vane in a gas turbine,comprising an outer body portion, said outer body portion being providedinteriorly thereof =with a recess, a core member in said recesscomprising metallic reinforcing means, said core member being of theform of an approximately circular segment, the surfaces of said coremember being complementary to the surfaces 'of the walls of said recess,said first-named and said second-named surfaces being in mutual contact,said outer body portion being made of ceramic material, means Y adaptingsaid outer body portion to withstand heat shocks,

said last-named means being comprised by the structure of said outerbody portion, said structure comprising a plurality of lamina membersforming said outer body portion, saidlamina members having planesurfaces extending transversely of the longitudinal direction of. saidcore member, the said plane surfaces of adjacent lamina members being inmutual contact, said lamina members being positioned one above theotherin said longitudinal direction and being essentially identical.

References Cited in thefile of this patent UNITED STATES PATENTS

1. A VANE CONSTRUCTION FOR FLOW DEVICES EXPOSED TO A RELATIVELY HIGHTEMPERATURE, ESPECIALLY FOR USE AS GUIDE VANES IN GAS TURBINES,COMPRISING AN OUTER BODY PORTION MADE OF CERAMIC MATERIAL AND FORMINGTHE VANE BODY, SAID CERAMIC BODY PORTION BEING PROVIDED WITH RECESSMEANS, AND METALLIC REINFORCING INSERT MEANS IN SAID RECESS MEANS FORSUPPORTING THEREON SAID CERAMIC BODY PORTION, SAID CERAMIC OUTER BODYPORTION HAVING A STRUCTURE ADAPTING SAID BODY PORTION TO WITHSTAND HEATSHOCKS, SAID STRUCTURE COMPRISING A PLURALITY OF LAMINA MEMBERS HAVINGABUTMENT SURFACES ABUTTING EACH OTHER, SAID SURFACES EXTENDINGESSENTIALLY TRANSVERSELY WITH RESPECT TO THE LONGITUDINAL DIRECTION OFSAID BODY PORTION SAID LAMINA MEMBERS BEING EMPLACED OVER SAID METALLICREINFORCING INSERT MEANS.